/* 课程详情页面样式 */
.course-detail-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 30px;
}

/* 课程头部信息 */
.course-header {
    grid-column: 1 / -1;
    display: flex;
    gap: 30px;
    padding: 30px;
    background: #f8f9fa;
    border-radius: 8px;
    margin-bottom: 30px;
}

.course-cover {
    width: 280px;
    height: 180px;
    object-fit: cover;
    border-radius: 4px;
}

.course-header-info {
    flex: 1;
}

.course-title {
    font-size: 24px;
    margin-bottom: 15px;
}

.course-meta {
    display: flex;
    gap: 20px;
    color: #666;
    margin-bottom: 15px;
}

.course-description {
    color: #444;
    line-height: 1.6;
}

/* 侧边栏导航 */
.course-sidebar {
    position: sticky;
    top: 20px;
    height: fit-content;
}

.course-progress {
    background: white;
    border-radius: 8px;
    padding: 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}

.progress-bar {
    height: 8px;
    background: #e9ecef;
    border-radius: 4px;
    margin: 10px 0;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: #28a745;
    transition: width 0.3s ease;
}

.chapter-list {
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.chapter-item {
    border-bottom: 1px solid #eee;
}

.chapter-header {
    padding: 15px 20px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.chapter-header:hover {
    background: #f8f9fa;
}

.chapter-content {
    display: none;
    padding: 0 20px;
}

.chapter-content.active {
    display: block;
}

.lesson-item {
    padding: 10px 0;
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
}

.lesson-item:hover {
    color: #007bff;
}

.lesson-icon {
    width: 20px;
    height: 20px;
}

/* 主要内容区域 */
.course-main {
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

/* 内容标签页 */
.content-tabs {
    display: flex;
    border-bottom: 1px solid #eee;
}

.tab-item {
    padding: 15px 30px;
    cursor: pointer;
    border-bottom: 2px solid transparent;
}

.tab-item.active {
    border-bottom-color: #007bff;
    color: #007bff;
}

.tab-content {
    display: none;
    padding: 30px;
}

.tab-content.active {
    display: block;
}

/* 课件内容样式 */
.content-viewer {
    margin-bottom: 30px;
}

.video-player {
    width: 100%;
    aspect-ratio: 16/9;
    background: #000;
    margin-bottom: 20px;
}

.document-viewer {
    width: 100%;
    min-height: 500px;
    border: 1px solid #eee;
    margin-bottom: 20px;
}

/* 讨论区样式 */
.discussion-section {
    margin-bottom: 30px;
}

.comment-form {
    margin-bottom: 20px;
}

.comment-input {
    width: 100%;
    height: 100px;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    margin-bottom: 10px;
    resize: vertical;
}

.comment-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.comment-item {
    border-bottom: 1px solid #eee;
    padding-bottom: 20px;
}

.comment-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 10px;
}

.comment-user {
    font-weight: 500;
}

.comment-time {
    color: #666;
}

.comment-content {
    line-height: 1.6;
    color: #444;
}

/* 笔记区域样式 */
.notes-section {
    margin-bottom: 30px;
}

.note-form {
    margin-bottom: 20px;
}

.note-input {
    width: 100%;
    height: 150px;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    margin-bottom: 10px;
    resize: vertical;
}

.note-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.note-item {
    background: #f8f9fa;
    padding: 15px;
    border-radius: 4px;
}

.note-time {
    color: #666;
    font-size: 14px;
    margin-bottom: 10px;
}

.note-content {
    line-height: 1.6;
}

/* 响应式设计 */
@media (max-width: 992px) {
    .course-detail-container {
        grid-template-columns: 1fr;
    }

    .course-header {
        flex-direction: column;
    }

    .course-cover {
        width: 100%;
        height: auto;
    }
}

@media (max-width: 768px) {
    .content-tabs {
        flex-wrap: wrap;
    }

    .tab-item {
        flex: 1;
        text-align: center;
        padding: 15px;
    }
}
